Personal watercraft typically employ a jet pump for generating a directed rearward stream of water which provides the forward thrust required to propel the craft and its occupants. The direction of propulsion is controlled by the positioning of a movable steering nozzle which receives the stream of water from the pump and directs the flow so as to divide the thrust into the desired directional components. The positioning of the nozzle is affected by a steering cable system which connects the nozzle to a handlebar controlled by the driver of the watercraft. The handlebar typically includes a throttle control and an electrical on and off switch.
Importantly, personal water craft are generally manufactured without braking or auxiliary control mechanisms rely on propulsion for control (steering), and reduction of propulsion for slowing. As such, the risk of dangerous accidents involving such watercraft has increased due in large part to the poor braking of the devices and the lack of indication that a personal water craft is slowing or changing direction. This fact is exacerbated by the lack of protection offered to a pilot or rider of water craft.
Attempts have been made to overcome the problem of a personal water craft having no ability to slow itself. One such attempt is disclosed in U.S. Pat. No. 7,007,621. This document also gives an excellent summary of the reasons for that invention which are repeated below verbatim.
“Currently, no satisfactory means are provided for braking the PWC. Auxiliary braking mechanisms are rarely, if ever, utilized. Instead, the throttle must be operated to reduce propulsion so that the PWC will gradually slow. This technique is far from satisfactory. For one thing, when the PWC is operating at a high speed, it can take too long for the vessel to slow to a stop. When the PWC is operating at a speed of 60 mph, for example, it can take up to 300 feet to achieve a complete stop. This obviously subjects the PWC and its rider(s) to the risk of a deadly collision with objects in the water that are too close to avoid. This problem is complicated because most personal watercraft are able to properly steer only when operated under full throttle. When the speed is reduced for braking, control is similarly reduced.
Prior attempts to achieve improved PWC braking have been generally unsuccessful. Reversing operation of the jet nozzle puts enormous and potentially damaging strain upon the nozzle. Fritchle, U.S. Pat. No. 6,691,634 discusses the problems associated with conventional PWC braking systems in considerable detail. That reference discloses a hand-operated mechanism for both controlling and braking operation of the PWC. A pair of braking paddles are mounted about the jet nozzle, which has no capability for directional adjustment. The paddles perform all of the steering, as well as the braking for the PWC. This ignores the fact that most personal watercraft employ a directionally adjustable nozzle and do not require such paddles for steering.”
There are also other similar braking devices disclosed in U.S. Pat. No. 5,092,260 to Mardikian (1992), U.S. Pat. No. 5,934,954 to Schott et al. (1999) and U.S. Pat. No. 5,607,332 to Kobayashi et al. (1997).
The prior art has developed seeking a solution to providing a means for slowing a personal water craft rather than developing means for indicating when a personal water craft is slowing.
A pilot or rider of a water craft also finds it relatively simple to judge the speed of a water craft from side on to the vessel by observing the vessel and the wake left behind as it makes way across the water. By the length of the wake, a judgment can be made of its speed. From in front of or behind the vessel though, the ability to judge speed and distance is difficult as a human relies on depth of perception to make this calculation. Also, the wake width is less obvious from the front or rear with a change in speed.
The inventor of the present invention believes that an indicator of this type will decrease the number of accidents involving personal water craft more effectively than providing braking mechanisms as an indicator allows other craft to be made aware of changes in velocity, which in turn allows other craft to evade or account for the slowing. Providing a braking mechanism only partly solves the issue of minimising accidents involving water craft as the craft itself may slow, but give no indication to other water craft.
It will be clearly understood that, if a prior art publication is referred to herein, this reference does not constitute an admission that the publication forms part of the common general knowledge in the art in Australia or in any other country.